With their purple flowers, lavenders can easily replace fountain grass. There are many species and varieties of lavender. Sweet lavender is able to tolerate a wide range of conditions including heat, humidity and cold. Other popular varieties of lavender are goodwin creek gray, French, and English lavender. They are fragrant and grow to about 1 1/2 to 2 feet tall and bloom with bright lavender flowers which can be dried for lavender fragrance.